1. Field of the Invention
The present invention relates to an image pickup apparatus, an image pickup method, and a non-transitory computer-readable medium storing a computer program for performing a pixel shift to generate high-resolution combined image data.
2. Description of the Related Art
There has been proposed a technique for combining a plurality of image data, which are acquired by performing a pixel shift with a movement amount that is a non-integer multiple of a pixel pitch, and generating high-resolution combined image data.
For example, Japanese Patent Application Laid-Open Publication No. H6-225317 describes a technique for shifting an image sensor of a Bayer array in a horizontal direction, a vertical direction, or an oblique direction by 0.5 pixel or one pixel at a time to perform four or eight times of photographing and combining obtained four or eight images to thereby generate an image having double resolution in the horizontal direction and the vertical direction.
Such a technique for combining images of a plurality of frames to obtain one high-resolution image is based on the premise that an object does not move while the images of the plurality of frames are photographed. Therefore, conventionally, photographing is performed in a procedure for, when exposure in one pixel shift position ends, performing capturing of an image, when the capturing of the image ends, performing a shift to a next pixel shift position (the pixel shift is referred to as “shift” as well), and, when the shift ends, starting next exposure. A photographing time required for the pixel shift photographing in this case is represented as follows:(exposure time+image capturing time+pixel shift time)×number of photographed images